METHOD FOR PRODUCING HIGH-PURITY CHLOROPOLYSILANE

摘要

[Problem] Chloropolysilane having a low metallic impurity concentration has been required to be obtained in order to be used for semiconductor applications. However, it is difficult by distillation to remove impurities such as a titanium compound having a vapor pressure close to that of chloropolysilane and an aluminum compound having a sublimating property. Meanwhile, when the content of metallic impurities such as aluminum and titanium reduces in metallic silicon that is a raw material, chlorination reaction is less likely to occur unless a reaction temperature is raised and that causes equipment to be restricted. It is found that a chlorination reaction can be carried out at a relatively low temperature by heating a mixture of granular metallic silicon and metallic copper or a copper compound in an inert atmosphere even when the metallic silicon has a high purity and does not contain aluminum and titanium and that chloropolysilane of high purity can be obtained by further adding metallic silicon as needed after the chlorination reaction is started.